Nutritional value

“ The quantities of nutrients in these food materials are approximately as follows:
Ration for Man at Moderate Work
It is to be noted that this ration contains approximately the amount of protein called for in the standard [Pg 266] ration, while the fat is slightly more and the carbohydrates are less. The food value of the ration is practically that called for in the standard. This ration is sufficiently near the standard to supply the nutrient requirements of a man at light muscular work. To supply palatability, some fruit and vegetables should be added to the ration. ”

“ Properly balanced rations will enable Innate Intelligence to promote the growth and maintain the processes of the body with the greatest ease and the least necessity for the adaptative expenditure of internal energy. Much attention has been given the science of nutrition. At one time there was great importance attached to the chemical composition of foods, special attention being given to the proteins, carbohydrates and fats contained in the diet. Later it was thought that certain inorganic salts were necessary. Great stress has been placed upon the caloric value of food. ”

“ It is a good plan to so arrange the daily diet that a combination of starch, sugar, fats and muscle-building foods may be had. Most of us, however, do not have the time or experience necessary to analyze the food we eat to learn its construction and relative food value. ”

“ The proteins or nitrogenous foods include all animal foods except fats, fish, crustaceans, eggs, milk and its products, certain vegetables, especially the lentils, that is, peas and beans, and gelatine. The fats include various fats and oils commonly eaten. The carbohydrates are the starchy foods, as cereals, sugars, fruits, and most vegetables, in fact, practically all except the lentils. Various beverages and condiments have no great nutritive value but serve to stimulate the appetite and to excite the secretion of the digestive juices. ”

“ No single natural order contains plants that supply all the elements essential to the nutrition of the body and the right composition of the blood. The graminaceous and leguminous articles of food, for instance, are numerous, but not various; they all afford the same or analogous albuminous elements, which have about the same nutrient value as the corresponding substances in animal food, and hence health and vigor cannot be sustained on a diet of flesh, combined with wheat, rice, and oatmeal or with beans and peas, or with all of them together. ”

“ Prominence is given in this work to those foods, as flour, bread, cereals, vegetables, meats, milk, dairy products, and fruits, that are most extensively used in the dietary, and to some of the physical, chemical, and bacteriological changes affecting digestibility and nutritive value which take place during their preparation for the table. Dietary studies, comparative cost and value of foods, rational feeding of men, and experiments and laboratory practice form features of the work. ”

“ The unique value of sugar depends upon its intelligent use and its proper combination with other foods, particularly with those rich in the nitrogenous compounds or proteids. Sugar alone is incapable of sustaining life, but combined with other foods is a valuable nutrient. ”

“ In the laboratory and by experimentation with human subjects the value of all foods has been very scientifically demonstrated. Foods largely consist of proteins, fats and carbohydrates, which have the function of supplying the body with energy or the power to work. The proper proportion of these constituents of food makes up a balanced ration which satisfies our physical needs in the way of nourishment. We get our carbohydrates from bread, fruits, vegetables, sugar and all grain products. ”

“ Hence it is [Pg 217] that the value of a food is dependent not alone on its composition, but also on its digestibility. The digestible or available nutrients of a food are determined by multiplying the per cent of each nutrient which the food contains by its digestion coefficient. For example, a sample of wheat flour contains 12 per cent protein, 88 per cent of which is digestible, making 10.56 per cent of available or digestible protein (12 × 0.88-10.56) . ”

“ That is to say, the digestible and available non-nitrogenous constituents of the food determine its nutritive value, provided always the moderate required supply of nitrogenous materials is present, and the comparative manurial value is determined by the nitrogenous constituents. A variety in the ration would undoubtedly be desirable for nutritive purposes, as the best results can not be obtained with any single article of diet. ”

“ Milk also provides protein, riboflavin, vitamin A, and many other nutrients. Cheese and ice cream also supply these nutrients, but in different proportions.
The bread-cereal group, with its whole-grain and enriched bread and other cereal products, furnishes important amounts of protein, iron, several of the B-vitamins, and food energy.
Fats, oils, sugars, and sweets are not emphasized in the guide because they are common in every diet. ”

“ Mixed Dietary Desirable.—Experiments in the feeding of farm animals show that the best results come from the combination of a number of foods to form a mixed ration, rather than from the use of one food alone, [79] for in this way the work of digestion is more evenly distributed, and a higher degree of efficiency is secured from the foods consumed. The same is true in human feeding; the best results are secured from a mixed diet. Ordinarily, about two fifths of the nutrients of a ration are derived from animal and three fifths from vegetable sources. ”

“ Each of the broad food groups has a special contribution to make toward an adequate diet.
Here are some of the reasons different food groups are emphasized in the guide and the names of some of the nutrients these foods provide.
Meat, poultry, fish, and eggs from the meat group and their alternates—dry beans, dry peas, and nuts—are valued for their protein. This is needed for the growth and repair of body tissues—muscle, organs, blood, skin, and hair. These foods also contribute iron and the B-vitamins—thiamine, riboflavin, and niacin. ”

“ In digestion experiments with oatmeal and milk, it was found that when these foods were consumed in large quantities the fat and protein were not as completely absorbed by the body as when less was used, the protein being 7 per cent and the fat 6 per cent more digestible in the medium ration. Experiments with animals show that economical results are not secured from an excess of food. [5] Some individuals consume too much food, and [Pg 225] with them a restricted diet would be beneficial, while others err in not consuming enough to meet the requirements of the body. ”

“ Within the last ten years the fact has been established (which was more or less guessed and acted upon by medical men of past days) that, in order to maintain health, the diet of man and of many animals must contain not merely the necessary quantities of meat or cheese-like bodies, of fat and starch and sugar, but also minute quantities of accessory food-factors which it is convenient to term "vitamines." ”

“ The nutrients are: first, the proteids or nitrogenous substances, which are found in meat, fish, eggs, milk, cheese, peas, beans, etc.; second, the carbohydrates, which include sugars and starch; and third, the fats, which are found in butter, oil, the fat of meat, etc. In addition to the nutrients, water and certain mineral salts are essential to life, while some indigestible material like the fibre of vegetables is needed to give bulk and to stimulate the action of the intestines.
The nutrients furnish the body with materials for growth, and for repair of tissues worn out by use ”

“ The proper adjustment of the relative quantities of the great groups of nutritive elements in the food is a matter the importance of which cannot be over-rated, for it is in fact the foundation of successful and economical feeding; and this will be readily understood if we consider what would be the result of giving to an animal a supply of food containing a large quantity of nitrogenous and a deficiency of fat-forming compounds. ”

“ Hard and fast rules governing the amounts of nutrients to be consumed cannot as yet be formulated, as our knowledge of the subject is too limited. It is known that both excessive and scant amounts are alike injurious. While the appetite may indicate either hunger or satiety, it alone cannot always be relied upon as a safe guide for determining the amount and kind of food to consume, although the demands of appetite should not be disregarded until it has been demonstrated beyond a doubt that it is not voicing the needs of nature. ”

“ But if the scales do not tell a too startling story, the chances are needed weight can be taken on or surplus fat taken off simply by paying more attention to diet.
Remember, however, in either event, we must not tamper with the proper supply of proteins, vitamins, and minerals. The body does not store proteins and must have its adequate supply each day. To fall below the right daily amount of vitamins and minerals also is to court trouble. ”

“ A child must have protein food in order to grow; an adult must have it in order to replace the tissues worn out by daily work. Also, there are certain peculiar and so far little understood elements, called vitamines, found only in certain kinds of food, notably fats, milk and the green vegetables, which are essential to the proper metabolism of the body. ”

“ To secure a proper and complete nutrition of the body it is desirable that all these elements should be so adjusted as to provide for complete nourishment without having any one of them in great excess. It is evident that an excess of any one or more of these nutrient materials must necessarily impose on the organs of the body an additional work in securing their proper elimination. ”

“ The ideal diet determined by weight, height, occupation and general health of the individual contains just sufficient quantity of fat and carbohydrates to give the required amount of heat and energy. In popular terms, one-fifth of the diet should consist of fat. Much of this may be fat of vegetables or meats, but some of it should be butter fat or its equivalent, especially for children because of the vitamines it contains. ”

“ In fact, among the cheap foods are some consisting mostly of protein, some consisting mostly of fat, and some consisting mostly of carbohydrate. For instance, cheap sources of protein are skim milk, beans, cheese, and peanuts. Cheap sources of fat are oleomargarine and cottonseed-oil. Cheap sources of carbohydrate, i.e., starch and sugar, are bread, bananas, potatoes, glucose, and even ordinary sugar. If a diet, selected for cheapness, is not at first well balanced, a judicious admixture of one or more of the foods just mentioned, will restore equilibrium. A cheap bulky food is cabbage. ”

“ Vitamins a New Factor in Nutrition.—But recent investigation has proved that something more is essential for the maintenance of growth and well-being than protein, carbohydrates, fats, and salts; that food contains a minute portion of accessory bodies, and that when they are deficient or absent from the diet the immature body does not grow, the mature body does not maintain its condition, and there are manifestations of more or less serious disease. ”

“ They serve the same purpose as fat.
All dietitians are agreed that protein is the essential combined in food. Deprivation of it quickly produces a starved physical condition. The actual quantity required cannot be determined with perfect accuracy, although estimates can be made approximately correct. The importance of the other nutrient compounds is but secondary. But the system must have all the nutrient compounds in correct proportions if it is to be maintained in perfect health. ”

“ These contain less fat, less nitrogenous matter, more water, and more sugar (or starch, which becomes sugar during digestion) than animal food.
Those who advocate the use of flesh food usually do so on the ground that it is more nutritious, contains more nitrogenous material and more fat than vegetable food. So much the worse for the human being, says Nature, when she prepares the food. ”

“ The diet should also be balanced according to the chemical needs of the body heretofore mentioned. In a a majority of cases, when the food scientist can prevail upon his patient to confine himself to a normal quantity of food, reasonably well balanced as to nutrient elements, the stomach will perform its natural functions, and fermentation with its long train of ills will gradually disappear. ”

“ The measurement and tabulation of food values in terms of calories and the investigation of the calorie needs of men and women in various occupations has been one of the great contributions of the past twenty years of nutritional study and to the progress made we owe our power to produce proper rations for every type of worker. ”

“ Secondly, the food which we eat does not always contain the proper proportions of the different kinds of nutritive ingredients. We consume relatively too much of the fuel ingredients of food, such as the fats of meat and butter, the starch which makes up the larger part of the nutritive material of flour and potatoes and sugar and sweetmeats. Conversely, we have relatively too little of the protein of flesh-forming substances, like the lean of meat and fish and the gluten of wheat, which make muscle and sinew and which are the basis of blood, bone and brain. ”